Propeller.



PATENTED APR. 21, 1908.

G. W. HOPKINS, DEGD.

M. HOPKINS. ADMINISTRATRIX.

PROPBLLER.

APPLICATION FILED AUG. 19, 1901.

IN VEN TOR B o 5 State 'of ew York, have-invented certain UNITED STATES PATENT OFFICE.

' GEORGE W. HOPKINS, OF BROOKLYN, NEW YORK; MARTHA HOPKINS ADMI'NISTRiATRIX OF SAID GEORGE W. HOPKINS, DECEASED.

PROPELLER.

Specification of Letters' Patopt.

Patented April 2 1, 1908.

Application filed August 19, 1907. Serial nit 389,101.

' To it may concem:

Be'it known that I, GnoneaW. HOPKINS, a citizeniof .the United States, and residin in the county of Kings and new and useful Improvements in Propellers,

' 1 of which the following is a specification,

such as will enable those skilled in the art to which it appertains to make and use the same.

The object of this invention is to provide .an' im roved propellerthe form and construction of which is such as to reduce churning to a minimum and also such as to give the greatest possible power to the propeller in pro ortion to the size or dimensions thereof? The invention is fully disclosed in the following specification, of which the accompanying drawing forms a part, in which the separate arts of my im rovement are designater b suitable re erence characters in each of t e views, and in which Figure '1 a side view of. m improved propeller, and Fig. 2 a front en view thereof.

Iii the practice of my invention, I provide a propeller com rising a hub w and s irall arran edblades ,two of which are emp oye t e blades btaper from. the rear ends f it itliereof. forwardlyy as; clearly shown the faring..- The comparativedimens ons of parts. of my ropeller are aslfollo'wsz the -"le h of the hu Qateninehes diameter of 'sai v hub two ands halfinches; width of the blades b, at their rear ends-b thereof, four inches; widthof said blades, at the.front ends 15 thereof ,;one-half inch. It will thereforebe seen thatthe taper of. the blades 11 is 'v. abrupt though grltdual and the rear s .or edges b of the blades are'tangential riphery of the hub of the propeller, and this construction'givestosaid lades at their rear ends great power and also reduces the tendency to churn;

presence It will also be seen that the separate spiral.

blades 11 do not extend entirel around the hub 11, and the taper thereof is ma e comparatively great so as to give to the rear end portions of said blades the required width and power, and the cur've-of the s iral of said blades is less 'than it woilld be, i said blades were carried entirely around the hub, and the fric tion caused by the o eration of the ropeller is decreased and at t 1e same time tfie power thereof is increased. [The rear outer corners of the blades I) also project slightly beyond the rear end of the hub a which also adds to y the power of said blades, andthe power of said blades in propelling a vessel forwardly increases in proportion to the transverse width thereof from the forward ends thereof iiearl to the extreme rear ends thereof. The rent end of the hub a is also preferably tapered as shown at a", and I have also shown the ordinar pro eller shaft c to which the pro" eller is eye as shown at d. i

I avin'g fully described my invention, what I claim-as new and desire to secure by Letters Patent, is:- J I A propeller comprising a central hub which is cylindrical in form in cross section and provided with two spiral blades which do not extend entirel around the hub, and the width of which increases rapidly from ,the front end thereof to the rear end thereof and the 'radial width of which is greatest at therear end where they terminate n straight lines'whieh are oblique to the axis of the hub and a proximately tangential to the peripherythereof. f w

In testimony that I claim thefo'regoing as my invention I have si ed my name in of the subscribing witnesses this 17th day of Au ust 1907. i

EORGE W. HOPKINS. Witnesses: 0. E. MULREANY, Lawaanos QUINN. 

